Critical Vapour Quality Measurement during R1233zd(E) flow boiling in a microfin tube

This paper presents the results of an experimental approach developed to measure the critical vapour quality at the onset of the dryout during flow boiling heat transfer of R1233zd(E) inside a microfin tube. The microfin tube under investigation has a 4.2 mm fin tip diameter, 40 fins, 0.15 mm high with an apex angle. equal to 42 degrees while the helix angle ss is 18 degrees. Sixteen calibrated T-type thermocouples were located just 1 mm below the tube to monitor the wall temperature to detect the onset of the dryout. The experimental measurements were carried out at a constant mean saturation temperature of 30 degrees C, by varying the refrigerant mass velocity between 100 kg m (2) s (1) and 300 kg m (2) s (1), the mean vapor quality from 0.1 to 0.95, and the heat flux from 15 to 90 kW m(-2).